Understanding Voltages in a circuit

Please look at the simple circuit and help me understand the concept of voltage.

1. Assume the circuit is in open condition. What would the voltage between point B and ground ? - Please answer this and help me understand a bit more clearly.


2. Assume the circuit is closed and current flows through it.

2a. What would be the value of voltage between point A and ground ?
2b. What would be the value of voltage between point B and ground ?

Please explain with some reason and in simple english. An example or analogy for the answers would be really great. Thanks.

 

With Switch closed.
A is across the battery so A to GND has Battery Voltage.
B is same as ground. So No voltage

And Switch open.
A and B has same voltage respective to GND as battery since no current is flowing through circuit.

 

1. With the switch open the voltage at both A & B will be 10V. A is simply the battery voltage. There is no current flowing so the voltage across the resistor is zero (V = I * R) and therefore the voltage at B is the same as A, 10V.
2a. The voltage at A is unchanged. It is the voltage across the battery.
2b. With the switch closed, B is connected directly to ground so there is zero voltage between B and ground. The difference between A & B is now equal to the battery voltage.
A the voltage at A
B the voltage at B
V voltage across the resistor
I current through the resistor
R the value of the resistor
V = I * R
I = V / R
I = (A - B) / R
I = (10V - 0V) / 10Ω
I = 10V / 10Ω
I = 1 amp.

 

Thank you!

 

Thank you!